Hi Steve,
really happy with my Sx900. Styles suit me better than the Pa4x ones did.

I have my yamaha p121 connected via laptop/midi to Sx900, only because I prefer fully weighted keys, plus it gives me 73 notes vs 61.

Only time I miss Pa4x is when I need a technology fix ( recovering style junkie),
the style editing functions on korgs brilliant, Yamaha not so good.

Try and check one out before you decide. If deciding between Sx900/SX700, there are some differences, so check those out too.